Laser ablation of nanoscale features is of interest for the fabrication of nanodevices and for the development of analytic instruments for sampling materials at nanoscale dimensions. The size of the smallest ablated features is limited principally by the wavelength of the laser emission and by heat diffusion. A number of techniques have been recently developed for producing ablation features with submicrometer size. By taking advantage of the well-defined ablation threshold in materials, craters having sizes ranging from 0.7 to 1.2 μm were achieved in silicon using nanosecond ultraviolet (UV) pulses. Ablation features of the order of 200 nm have been demonstrated using femtosecond laser pulses in the near-infrared, and UV spectral regions. Patterning of yet smaller features has been achieved using the electric field enhancement created at the tip of an atomic force microscope (AFM) by focused femtosecond laser pulses or by using optical fibers to create near-field effects.
Accordingly, it is an object of the present invention to provide an apparatus and method for machining nanoscale features in materials by ablation using extreme ultraviolet/soft x-ray (EUV/SXR) radiation.
Another object of the invention is to provide an apparatus and method for patterning nanoscale features in materials by ablation using high spatial resolution extreme ultraviolet/soft x-ray radiation at wavelengths having small absorption depth in the materials.
Additional objects, advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.